questions on first solar setup

alter

Hello, I'm new to this and have some questions. I'm hoping someone with more experience can help me out. I have the following equipment:

Duracell DPP-600HD Powerpack 600
Sunforce 50044 60-Watt Solar Charging Kit

I realize the battery is only large enough for small appliances but if I can start with this I would like to expand it later. I'm basically trying to connect the solar panels to the powerpack to charge it, but so far I've been unsuccessful at getting it to take a charge. The charge controller keeps saying charging but also the "charged" light is lit up and it hasn't been charging it. Can I wire the solar panels into the DC port on the powerpack to charge it? What is the best way to go about this? Thanks for any help.

icarus

Re: questions on first solar setup

Couple of things,,

Looking at the web site,, it is a tiny battery, 28 ah,, with a maximum charge current of 1 amp. Your 60 watt panel will put out maybe 3-4 amps under full sun in cool conditions.

How are you connecting this to the solar panel? I can't see how you would wire a panel to this battery pack.

Tony

alter

Re: questions on first solar setup

Icarus,

The batter pack has a DC input that it can be supposedly charged from. I tried wiring the charge controller into a DC plug and plugged it into that. I'm now thinking it may be a faulty unit but not sure. I guess the next step would be to try a volt meter next to see if its getting a charge or if its an issue the charge controller.

icarus

Re: questions on first solar setup

Post the instructions for the unit if you can,,, I couldn't find them on line.

T

alter

Re: questions on first solar setup

Tony,

Here is a link to a specification sheet that may be useful. It indicates max charging time from DC is 4 hours...that's probably assuming its plugged into a car's DC outlet.

http://www.duracellpower.com/documents/tech-specs/DS20070710_duracell-pp600.pdf

BB.

Re: questions on first solar setup

You might be able to just clip the jumper cable output to the solar battery charger's output (if you have a meter, double check the voltages as the panels are exposed to sun--you should see the voltage slowly creep up).

In general, those little jumper/dc/ac inverter boxes are not very good for any application. Small battery and "large inverter" (which would kill the battery in less than 30 minutes if run at "full power").

You would usually be better off to define your needs (and verify with a totalizing watt*hour/kWhr meter such as: Kill-A-Watt meter for AC power, or a Watts-Up or Doc Watson for DC).

Once you know your power requirements in detail--then you can look at what hardware will work for you.

-Bill

niel

Re: questions on first solar setup

it says through that dc socket and it's possible that is fused and the fuse blew.
it also states charger input socket current is 2.5a max and this makes me think it is fused. that 2.5a max charge would contradict their charge time for a dead battery of 4hrs because 28ah/2.5a=11.2hrs.

alter

Re: questions on first solar setup

Bill,
Thanks I will definitely give that a try. Yeah I was not expecting much out of this, just wanted to get something working quickly. I do plan on using it for very minor things like watching tv on a small tv a couple hours a day and some lights for a few hours per day. My requirements are really not a lot. I would like to make a battery bank, and already have one "real" battery, its an Interstate SLA1156. I will buy a few more if it makes sense. Would a bank of say, four of these batteries be acceptable for use in a small solar system like this?

niel

Re: questions on first solar setup

that pv is large enough to maintain or float charge a few hundred amphours of battery capacity. to charge batteries we don't normally recommend less than 5% of the ah ratings of the batteries for a charge current. if you have, for example, 400ah of battery capacity, you are looking at a 20a charge source mimimally. your 60w pv might do 60w/17.4v=3.45a.

BB.

Re: questions on first solar setup

If you want AC--get the kill-a-watt meter. Very useful around home to help you conserve energy too...

Without knowing your loads (watts peak, and average watts*hours for total power used) -- it is difficult to estimate how much you need in the way of batteries, solar panels, and inverters.

In general, most people underestimate their power needs by 5-10x... It is not unusual. They use 2-3 times as much power, and by the time you go from solar panel name plate rating through real hours of full sun (~4-5 hours in the summer) through the losses of batteries and inverters--you get roughly an end to end loss of 52%--so 3 times more power times 1/52% means about ~6x more solar panels than a first guess would indicate.

A good 100+ Amp*Hour 12 volt battery would be good for a start... You could run a 500 watt load for ~1 hour, or a 100 watt load for 5 hours.

For a good 12 volt inverter--The Morning Star 300 watt (600 watt for 10 minutes) True Sine Wave inverter is about the best small unit out there--but they cost $250 instead of the $25 for a Modified Square/Sine Wave inverter (can cause some devices to run hot and/or fail).

-Bill

alter

Re: questions on first solar setup

Niel and Bill, thanks for the information.

Niel - I didn't quite understand all of that, but it sounds like with the solar panels I have, I should not make a battery bank with a capacity larger than a few hundred Amp Hours, ok I'll keep that in mind.

Bill - alright I will look into those products. If you have any recommendations on which battery (is one brand preferred more than others?) to use and how many if I were to use my panels to their potential. If I get a couple large batteries like the one you mentioned that would be more ideal than several smaller batteries I take it?

BB.

Re: questions on first solar setup

There are a lot of variables with batteries (and with any project).

Flooded cell batteries tend to be cheaper, and if you get true deep cycle batteries (not auto batteries, or marine/RV batteries)--you are off to a good start.

AGM's are probably the "best" type of battery out there--no water levels to check, much cleaner, resist sulfation problems better, etc.--However, they are very sensitive to over charging and easy to ruin.

Typically, a first time user is recommended to get "cheap" flooded cell battery set (golf car or larger) for a "training bank". Almost everyone (and I mean everyone) will ruin their first bank of batteries through over/under charging, over discharging, or improper watering/maintenance.

I personally like larger batteries (in series, if higher voltages are needed) vs smaller batteries in parallel (or series parallel). Fewer cells to monitor, fewer cables to manage... However, big batteries weigh a lot--so you have to make sure you can accept delivery and move them into your battery shed/area.

You can read Battery FAQ's (like this one) to get a better idea of what will work best for you.

Our host stands by their products--so I tend to recommend people look there first--but, in reality, batteries are heavy and costly to ship. Look at local suppliers too and see what they have/recommend.

There are still many questions to ask and answer--but regarding getting the best from your battery bank--I really like to push getting a battery monitor--the only way you can properly monitor AGM batteries underload or undercharge--and much less hassel than measuring specific gravity in flooded cell banks. Monitoring battery voltage is iffy at best.

The Trimetic is a good low cost unit. The Xantrex LinkLite/LinkPro have a programable output you can use to turn off an inverter/ring an alarm if the batteries are too discharged.

Anyway--look at your load requirements. And remember, that solar pay for itself best if used 9+ months out of the year... If this is for an emergency setup or summer weekend cabin--solar is much more difficult to justify.Then, many times a generator (such as a small Honda eu1000i or eu2000i) is a more practical solution (possibly with batteries for quite night time power).

Also--solar RE power is expensive--probably 10-20x the cost per kWhr vs your local utility power. Conservation is your first goal. Measure your loads, reduce to a minimum, and look at new/lower power devices where practicable.

It is almost always cheaper to conserve a watt*hour vs generating a watt*hour.

-Bill

niel

Re: questions on first solar setup

"Niel - I didn't quite understand all of that, but it sounds like with the solar panels I have, I should not make a battery bank with a capacity larger than a few hundred Amp Hours, ok I'll keep that in mind."

well, that's not exact;y what i was saying. what was said was that you need at least a minimum amount of pv for charging a battery and if you are limited in that charging source, it limits how large the batteries can be. if my rough 3.45a was accurate for your pv then 3.45/.05=69ah as a maximum size battery for your pv.
you need to grasp this concept of battery charging or risk not properly charging it and thusly ruining it.